Which is better: Lancome Definicils Precious Cells or YSL Exaggerated Lashes?

I'm getting tons of new beauty products for Christmas, and I need a few new great mascaras. Which of these is best? Which is more worth the price? Are they both worth it? Thanks a bunch!|||I am a die hard Lancome kind of girl. I knew the VP of Estee Lauder and she said it was the best she also told me that MAC had the longest lasting eyeshadows.